[Macrophage and platelets inhibit proliferation of methicillin-resistant Staphylococcus aureus in vitro]

Objective To investigate the effect of platelet and macrophage on the proliferation of methicillin-resistant Staphylococcus aureus (MRSA) in vitro, to explore the mechanisms of the inhibition effect, and to further reveal platelet function. Methods LB culture system with 4×10⁸ CFU/mL MRSA inoculation concentration was established in vitro. Leukocyte-free platelets with a number of 200×10⁹/L (platelet group) and macrophages with a number of 1×10⁹/L (macrophage group) were added, respectively. The system without platelets and macrophages was used as negative control (control group). The absorbance of bacterial solution of the two groups was measured for reflect the proliferation of MRSA at different time points. After 2 hours culture, the bacterial liquid was collected for plating after double dilution, and the concentration of bacterial liquid was obtained through calculation after colony counting. Flow cytometry was also performed to verify the phagocytosis of macrophages and the capture ability of platelets. Results Both macrophages and platelets showed suppressive effect on the proliferation of MRSA compared to control group, while the effect of platelets was more significant. Conclusion Platelets have stronger inhibitory ability on MRSA proliferation in vitro than macrophages.